This tutorial will show you how to change your lot so that vehicles willl drive on the other side of the road. Note that this is only one step in getting true right-hand drive into your game.

1) backup your save game!

2) Download and install the Portal Revealer. This will make your portals visible, so that you can move them around on your lot:
http://www.modthesims.info/download.php?t=251392

3) Run the game and enter your lot.

4) Type in the cheat "moveobjects on", to allow you to manipulate the portals.

5) Go to multi-story windows in build mode and place the Portal Revealer (which looks like a spotted flamingo) anywhere on your lot. You may have to pick it up and place it a second time for the portals to remain visible.

You should see 6 portals, which unfortunately all look alike: 2 pedestrian, 1 Car - Start, 1 Car - Stop, 1 Car - Service Start, and 1 Car - Service Stop. To determine which portal is which, you can pick the portal up and the game will identify it. You should see something like this:

You'll note that the portals are placed for the location of the left front tire.

For passenger vehicles, such as cars, carpools, buses, taxis, etc., Car Start is where the vehicle will first appear on your lot. Car Stop is where the vehicle will stop to pick up or discharge passengers. The direction of travel is shown as an arrow on the portals and cars will travel from Car Start to Car Stop, then from Car Stop to the edge of the lot.

Service vehicles have similar behavior, appearing on the lot at Service Start, stopping at Service Stop, and then continuing in the same direction until they reach the edge of the lot. You should be aware that service vehicles must have enough room to access the trunk when they stop.

There is some leeway as to where the portals are placed, but what I've shown is a pretty standard configuration.

6) To get vehicles to travel in the opposite direction, you will need to move and rotate the car and service portals like this:

Because the portals describe the location of the left front tire, the portals must be moved to the outside edge of the road (rather than beside the center line as they were before). I've moved the Car Start and Service Start to the opposite edges of the lot and rotated them to allow travel in the correct direction. The Car Stop and Service Stop have been moved to opposite sides of the walkway to the house and again rotated.

7) Once everything is placed correctly, delete the flamingo, save your game and test the lot. You can call a taxi to test the car portals and order pizza delivery to test the service portals. If you have any problems, post a picture of your portals or a picture of the vehicle behavior.

The rest of the puzzle:
If you want vehicles to travel on the opposite side of your road in neighborhood view, add the following line to your userStartup.cheat:
boolProp carsOnRight false

At this time, we don't know how to get the driver to sit on the other side of the car. I suspect that you will need default replacements for all of the vehicles in the game.

As well, the driveway will probably need to be flipped, since your sim will pull their car out of the driveway facing in the wrong direction.